Resuscitation device with expert system

ABSTRACT

A resuscitation device for automatic compression of victim&#39;s chest using a compression belt which exerts force evenly over the entire thoracic cavity. The belt is constricted and relaxed through a motorized spool assembly which repeatedly tightens the belt and relaxes the belt to provide repeated and rapid chest compression. An assembly includes various resuscitation devices including chest compression devices, defibrillation devices, and airway management devices, along with communications devices and senses with initiate communications with emergency medical personnel automatically upon use of the device.

This application is a continuation of U.S. application Ser. No.11/199,110 filed Aug. 8, 2005, now U.S. Pat. No. 7,996,081, which is acontinuation of U.S. application Ser. No. 10/630,505 filed Jul. 29,2003, now U.S. Pat. No. 6,926,682, which is a continuation of U.S.application Ser. No. 09/615,979 filed Jul. 14, 2000, now U.S. Pat. No.6,599,258, which is a continuation of U.S. application Ser. No.08/924,555 filed Aug. 27, 1997, now U.S. Pat. No. 6,090,056.

FIELD OF THE INVENTIONS

This invention relates to emergency medical devices and methods.

BACKGROUND OF THE INVENTIONS

Cardiopulmonary resuscitation (CPR) is a well-known and valuable methodof first aid. CPR is used to resuscitate people who have suffered fromcardiac arrest after heart attack, electric shock, chest injury and manyother causes. During cardiac arrest, the heart stops pumping blood, anda person suffering cardiac arrest will soon suffer brain damage fromlack of blood supply to the brain. Thus, CPR requires repetitive chestcompression to squeeze the heart and the thoracic cavity to pump bloodthrough the body. Very often, the victim is not breathing, and mouth tomouth artificial respiration or a bag valve mask is used to supply airto the lungs while the chest compression pumps blood through the body.

It has been widely noted that CPR and chest compression can save cardiacarrest victims, especially when applied immediately after cardiacarrest. Chest compression requires that the person providing chestcompression repetitively push down on the sternum of the victim at80-100 compressions per minute. CPR and closed chest compression can beused anywhere, wherever the cardiac arrest victim is stricken. In thefield, away from the hospital, it may be accomplished by ill-trainedby-standers or highly trained paramedics and ambulance personnel.

When a first aid provider performs chest compression well, blood flow inthe body is typically about 25-30% of normal blood flow. This is enoughblood flow to prevent brain damage. However, when chest compression isrequired for long periods of time, it is difficult if not impossible tomaintain adequate compression of the heart and rib cage. Evenexperienced paramedics cannot maintain adequate chest compression formore than a few minutes. Hightower, et al., Decay In Quality Of ChestCompressions Over Time, 26 Ann. Emerg. Med. 300 (September 1995). Thus,long periods of CPR, when required, are not often successful atsustaining or reviving the victim. At the same time, it appears that, ifchest compression could be adequately maintained, cardiac arrest victimscould be sustained for extended periods of time. Occasional reports ofextended CPR efforts (45-90 minutes) have been reported, with thevictims eventually being saved by coronary bypass surgery. See Tovar, etal., Successful Myocardial Revascularization and Neurologic Recovery, 22Texas Heart J. 271 (1995).

In efforts to provide better blood flow and increase the effectivenessof bystander resuscitation efforts, modifications of the basic CPRprocedure have been proposed and used. Of primary concern in relation tothe devices and methods set forth below are the various mechanicaldevices proposed for use in main operative activity of CPR, namelyrepetitive compression of the thoracic cavity.

The device shown in Barkolow, Cardiopulmonary resuscitator Massager Pad,U.S. Pat. No. 4,570,615 (Feb. 18, 1986), the commercially availableThumper device, and other such devices, provide continuous automaticclosed chest compression. Barkolow and others provide a piston that isplaced over the chest cavity and supported by an arrangement of beams.The piston is placed over the sternum of a patient and set to repeatedlypush downward on the chest under pneumatic power. The victim must firstbe installed into the device, and the height and stroke length of thepiston must be adjusted for the patient before use, leading to delay inchest compression. Other analogous devices provide for hand operatedpiston action on the sternum. Everette, External Cardiac CompressionDevice, U.S. Pat. No. 5,257,619 (Nov. 2, 1993), for example, provides asimple chest pad mounted on a pivoting arm supported over a patient,which can be used to compress the chest by pushing down on the pivotingarm. These devices are not clinically more successful than manual chestcompression. See Taylor, et al., External Cardiac Compression, ARandomized Comparison of Mechanical and Manual Techniques, 240 JAMA 644(August 1978). Other devices for mechanical compression of the chestprovide a compressing piston that is secured in place over the sternumvia vests or straps around the chest. Woudenberg, CardiopulmonaryResuscitator, U.S. Pat. No. 4,664,098 (May 12, 1987) shows such a devicewhich is powered with an air cylinder. Waide, et al., External CardiacMassage Device, U.S. Pat. No. 5,399,148 (Mar. 21, 1995) shows anothersuch device which is manually operated. In another variation of suchdevices, a vest or belt designed for placement around the chest isprovided with pneumatic bladders that are filled to exert compressiveforces on the chest. Scarberry, Apparatus for Application of Pressure toa Human Body, U.S. Pat. No. 5,222,478 (Jun. 29, 1993) and Halperin,Cardiopulmonary Resuscitation and Assisted Circulation System, U.S. Pat.No. 4,928,674 (May 29, 1990) show examples of such devices.

Several operating parameters must be met in a successful resuscitationdevice. Chest compression must be accomplished vigorously if it is to beeffective. Very little of the effort exerted in chest compressionactually compresses the heart and large arteries of the thorax and mostof the effort goes into deforming the chest and rib cage. The forceneeded to provide effective chest compression creates risk of otherinjuries. It is well known that placement of the hands over the sternumis required to avoid puncture of the heart during CPR. Numerous otherinjuries have been caused by chest compression. See Jones and Fletter,Complications After Cardiopulmonary Resuscitation, 12 AM. J. Emerg. Med.687 (November 1994), which indicates that lacerations of the heart,coronary arteries, aortic aneurysm and rupture, fractured ribs, lungherniation, stomach and liver lacerations have been caused by CPR. Thusthe risk of injury attendant to chest compression is high, and clearlymay reduce the chances of survival of the victim vis-á-vis aresuscitation technique that could avoid those injuries. Chestcompression will be completely ineffective for very large or obesecardiac arrest victims because the chest cannot be compressed enough tocause blood flow. Chest compression via pneumatic devices is hampered inits application to females due to the lack of provision for protectingthe breasts from injury and applying compressive force to deformation ofthe thoracic cavity rather than the breasts.

CPR and chest compression should be initiated as quickly as possibleafter cardiac arrest to maximize its effectiveness and avoid neurologicdamage due to lack of blood flow to the brain. Hypoxia sets in about twominutes after cardiac arrest, and brain damage is likely after aboutfour minutes without blood flow to the brain, and the severity ofneurologic defect increases rapidly with time. A delay of two or threeminutes significantly lowers the chance of survival and increases theprobability and severity of brain damage. However, CPR and ACLS areunlikely to be provided within this time frame. Response to cardiacarrest is generally considered to occur in four phases, including actionby Bystander CPR, Basic Life Support, Advanced Life Support, and theEmergency Room. By-stander CPR occurs, if at all, within the first fewminutes after cardiac arrest. Basic Life Support is provided by FirstResponders who arrive on scene about 4-6 minutes after being dispatchedto the scene. First responders include ambulance personnel, emergencymedical technicians, firemen and police. They are generally capable ofproviding CPR but cannot provide drugs or intravascular access,defibrillation or intubation. Advanced Life Support is provided byparamedics or nurse practitioners who generally follow the firstresponders and arrive about 8-15 minutes after dispatch. ACLS isprovided by paramedics, nurse practitioners or emergency medical doctorswho are generally capable of providing CPR, drug therapy includingintravenous drug delivery, defibrillation and intubation. The ACLSproviders may work with a victim for twenty to thirty minutes on scenebefore transporting the victim to a nearby hospital. Thoughdefibrillation and drug therapy is often successful in reviving andsustaining the victim, CPR is often ineffective even when performed bywell-trained first responders and ACLS personnel because chestcompression becomes ineffective when the providers become fatigued.Thus, the initiation of CPR before arrival of first responders iscritical to successful life support. Moreover, the assistance of amechanical chest compression device during the Basic Life Support andAdvanced Life Support stages is needed to maintain the effectiveness ofCPR.

SUMMARY

The devices described below provide for circumferential chestcompression with a device which is compact, portable or transportable,self-powered with a small power source, and easy to use by by-standerswith little or no training. Additional features may also be provided inthe device to take advantage of the power source and the structuralsupport board contemplated for a commercial embodiment of the device.

In its simplest form, the device includes a broad belt which wrapsaround the chest and is buckled in the front of the cardiac arrestvictim. The belt is repeatedly tightened around the chest to cause thechest compression necessary for CPR. The buckles and/or front portion ofthe belt are anatomically accommodating for the female breast, or forthe obese person, so that the device is effective for women as well asmen. The buckle may include an interlock which must be activated byproper attachment before the device will activate, thus preventingfutile belt cycles. The operating mechanism for repeatedly tighteningthe belt is provided in a support board, and comprises a rollingmechanism which takes up the intermediate length of the belt to causeconstriction around the chest. The roller is powered by a small electricmotor, and the motor powered by batteries and/or standard electricalpower supplies such as 120V household electrical sockets or 12V DCautomobile power sockets (car cigarette lighter sockets). (An initialprototype used a power drill with a single 9.6V rechargeable battery,and provided powerful chest compression for about ten minutes.) Thebatteries and any necessary transformers may be housed in the supportboard, and the support board may be made in sizes useful for supportingthe victim's head, adequate for storing batteries and other accessories,and convenient for mounting within office buildings, factories,airplanes and other areas of potential need. Thus, numerous inventionsare incorporated into the portable resuscitation device described below.

The portable resuscitation device may incorporate a number of featuresand accessories that aid in the administration of CPR and other therapy.By-standers may be unable to confidently determine if chest compressionis needed, or when it should be stopped. Accordingly, the device may becombined with an interlock system including a heart monitor or EKG whichdiagnoses the condition of the patient, and circuitry or a computerwhich initiates, permits or forbids belt operation accordingly. Thepower supply provided for belt constriction may also be used to providepower for defibrillation (an appropriate treatment for many cardiacarrests). Again, bystanders will most likely not be capable ofdetermining when defibrillation is appropriate, and the defibrillationportion of the device may be provided with an interlock system includingthe heart monitor or EKG which diagnoses the condition of the patientand circuitry which initiates, permits, or forbids defibrillation.Expert systems implemented through the circuitry or computer modules canaccomplish these functions.

Automatic, computer driven therapy of this nature may provide early andappropriate life saving response to many cardiac arrest patients whomwould otherwise die. However, some situations in which the device mightbe used may call for expert supervision of the CPR process by emergencymedical technicians, emergency room doctors, or cardiologists. To thisend, the expert systems mentioned above may be replaced with the expertdiagnosis and decision-making of medical personnel through a telemetrysystem housed within the support board of the device. The support boardcan include a telemetry system which automatically dials medicalpersonnel in a nearby hospital, emergency medical crew, ambulance, oreven a central diagnostic and control facility. Interlocks, limitswitches and other typical sensors can be used to sense the properposition and closure of the belt about the chest of the patient. Heartmonitors and EKG electrodes can sense the heart rate and EKG of thevictim. Using communication equipment within the device, thisinformation can be communicated from the device to medical personnelremote from the victim. Through the same system, the medical personnelcan communicate the device to initiate, permit or prohibit beltconstriction or defibrillation, as dictated by preferred medicalprocedures. Communication can be established through normal telephonelines and a cordless telephone, or through a cellular telephone system,paging system, Internet or any other communications system. The devicecan be programmed with location information, or provided with GPScapabilities to determine the location of the device, and thisinformation can be automatically transmitted to an emergency responsesystem such as the 911 system when the system is placed in use.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an overview of the resuscitation device, showing the inner andouter vests partially open.

FIG. 2 is an overview of the resuscitation device in the buckledconfiguration.

FIG. 3 is a detail view of the buckle used to close the device about avictim.

FIG. 4 shows the spool assembly used to operate the compression belt.

FIG. 5 shows an alternative embodiment of the spool assembly used tooperate the compression belt.

FIG. 6 is a view of the resuscitation device properly positioned on avictim.

FIG. 7 shows the resuscitation device fitted with a number of additionaldevices for use during resuscitation.

FIG. 8 shows a detail view of the CRP module of FIG. 7.

FIG. 9 shows a detail view of the defibrillation module of FIG. 7.

FIG. 10 shows a detail view of the airway management module of FIG. 7.

FIG. 11 shows a detail view of the control and communications module ofFIG. 7.

FIG. 12 shows a block diagram of the communications system.

FIG. 13 is a block diagram of the motor control system.

DETAILED DESCRIPTION OF THE INVENTIONS

FIG. 1 shows a simplified version of the resuscitation device 1. Themechanisms used for compressing the chest includes compression assembly2 which includes a chest compression belt 3 with buckles 4L and 4R, afriction liner 5, a support board 6 and a motor driven spool assembly 7.The support board 6 is placed under a cardiac arrest victim, and thecompression belt 3 and friction liner 5 are wrapped around the victim'schest. The chest compression belt, having a left side 3L and a rightside 3R, is buckled over the victims chest by latching the buckles 4Land 4R together. In this configuration, the friction liner 5 will fitbetween the chest compression belt 3 and the victim and any clothes wornby the victim. The compression belt may be made of any strong material,and sailcloth has proven adequate for use. The compression belt may alsobe referred to as a vest, corset, girdle, strap or band. The frictionliner may be made of Teflon®, Tyvek™ or any other low friction material(by low friction, we mean a material that will permit sliding of thecompression belt with less friction than expected between the belt andthe victims clothing or bare skin). The friction liner may be made withany suitable lining material, as its purpose is to protect the victimfrom rubbing injury caused by the compression belt, and it may alsoserve to limit frictional forces impeding the compression beltoperation. The friction liner can be provided in the form of a belt,vest, corset, girdle, strap or band, and may partially or completelyencircle the chest.

The front of the compression belt 3, including the buckles 4L and 4R,are configured to provide a broad pressure point over the sternum of thevictim. This is illustrated in FIG. 2. Large openings 8 may be providedto accommodate female breasts and obese male breasts. The underside ofthe buckles 4L and 4R are smooth and broad, to distribute compressiveforce evenly over a wide area of the chest corresponding to the sternum.The point at which the buckle attaches to the chest compression belt mayvary considerably, from the front of the chest to the back of thecompression assembly, and the openings 8 may be provided in the bucklesrather than the belt itself. FIG. 3 shows a detail of the buckles 4L and4R used to fasten the compression belt about the chest of the victim.The buckle may be of any type, and preferably includes a latch sensingswitch 9 operably connected through wire 10 to the motor control system(see FIG. 13) to indicate that the device has been buckled about thevictim's chest and is ready for the initiation of compression cycles.The buckles shown in FIG. 3 are D-ring shaped buckles with largeopenings 8, attached to the compression belt 3. Other fasteners andfastening means may be used.

The chest compression belt 3 is repeatedly tightened about the chest ofa victim through the action of one or more tightening spools which makeup the spool assembly 7 located within the support board 6. The spoolassembly, illustrated in FIG. 4, includes at least one spool or reelconnected to the compression belt 3 at the back of the belt, preferablynear the center or saggital line 11 of the compression belt (although itmay be located on the front or side of compression belt). FIG. 4 shows aview of the spool assembly and its attachment to the compression belt. Aspool assembly includes a single drive spool 12 operably connected tothe motor 14 through drive shaft 15. The compression belt is secured tothe drive spool in any suitable manner. In this case a longitudinal slot16 provided in the drive spool 12. The slot extends radially orchordally through the drive spool, and extends axially for a lengthcorresponding to the width of the compression belt, leaving the ends 17solid for connection to the drive shaft 15 and journal shaft 18. Thebelt is slipped through the slot to create a secure connection betweenthe belt and the drive spool. When secured in this manner, the rotationof the drive spool 12 will take up the right side of the compressionbelt 3R and the left side of the compression belt 3L and roll them uponto the spool, thus tightening the compression belt about the chest ofthe victim wearing the device. Spindles or alignment rollers 19 providefor alignment and low friction feed of the belt onto the roll created byoperation of the drive shaft.

Many alternative embodiments can be envisioned for the rollingmechanism, and one such alternative is illustrated in FIG. 5. Spools 12Land 12R are aligned in parallel and interconnected by a transmissiongear 20 and planetary gear 21 and journaled upon shafts 18L and 18R. Thedrive shaft 15 is attached to spool 12R (or spool 12L) and operablyattached to motor 14. The motor turns the shaft 15 and spool 12R in acounterclockwise direction to pull the right side of the compressionbelt 3R to the left and roll onto the spool. The transmission gear 20acts upon the planetary gear 21 to cause clockwise rotation of spool12L, which in turn pulls and wraps the left side of the compression belt3L onto the spool 12L.

Thus, many embodiments of mechanisms which can cause repeated cyclictightening of the compression vest about the chest of the victim may beenvisioned. The compression belt serves to radially compress the chestthrough the cooperative action of the belt, board, and buckle, and todisperse the compressive force around the chest.

The motor is energized to rotate the spools and cause the compressionbelt to constrict around the chest of a victim. A motor such as abattery operated hand drill motor provides adequate chest compressionfor the purposes of CPR. To cause repetitive constriction of thecompression belt 3, the motor 14 must be attached via a clutch 22 orother such mechanism. The motor 14 may be attached to the drive shaft 15through a torque slipping clutching mechanism which engages the driveshaft until a high torque is achieved (indicating great resistance tofurther constriction, and thus indicating that the victim's chest hasbeen compressed), and releases automatically upon such high torque, onlyto re-engage after the belt has been expanded in response to the normalelastic expansion of the victim's chest. In this manner, repetitivecompression is achieved without need to repeatedly energize andde-energize the motor, thereby extending the length of operating timefor any given battery supply. Alternatively, the motor may be repeatedlyenergized and de-energized, with the spools spinning freely duringperiods in which the belt is de-energized, wherein the clutch mechanism22 will be similar to clutch mechanisms used on electric drills (whichengage during operation of the drill but spin freely when the drill isde-energized). While the natural elastic expansion of the chest shouldmake it unnecessary to drive the belt toward a loose condition, positiveloosening may be achieved by reversing the motor or reversing the actionof the motor through appropriate clutch or gear mechanisms. Timing ofcompressions is regulated through a computer module or a simple relay(windshield wiper style relays), and preferably will conform to standardof the Advanced Cardiac Life Support guidelines or CardiopulmonaryResuscitation guidelines, or any other medically acceptableresuscitation regime. Current guidelines put forth by the American HeartAssociation call for 60-100 chest compressions per minute.

The motor is preferably battery powered, with provisions for takingpower from any available power source. Batteries 23 may be stored withinthe support board 6. Three-volt batteries of convenient size, alreadyavailable for use with numerous power tools, provide about five minutesof compression per battery, while twelve-volt batteries (1700 mA-h perbattery) have provided about ten minutes of compression per battery. Athirty minute total battery capacity is desirable (corresponding to theestimated average time between cardiac arrest and transport to thehospital). Accordingly, several batteries may be installed within thesupport board and electrically connected to the motor and itscontroller. The batteries are provided with a trickle charge through acharger socket and charger plugged into 120V AC power when the device isnot in use. (It is intended that the device be installed in factories,office buildings, airplanes and other facilities with relatively stablesources of power, and that the unit remain plugged in and charging whennot in use.) If AC power is readily available at the site of use, thedevice may continue to run on AC power to preserve the batteries forlater use. The unit may also be plugged into an automobile power jackwith an appropriate auto adapter, thus providing for use where anautomobile is the only source of power and for extended use in anambulance.

FIG. 6 shows the resuscitation device installed on a cardiac arrestvictim. The support board is placed under the victim, and the right andleft portions of the compression belt are wrapped around the victim'schest and buckled over the front of the chest, indicated by arrow 25.Once in place, the system may be put into operation by manually startingthe motors or by automatic initiation given the proper feedback fromsensors located on the device, including the buckle latch sensors.

A number of features may be combined with the basic system describedabove. The structure necessary for housing the operating mechanism forthe belt, referred to as the support board above, can serve also asstorage for additional devices used during resuscitation. FIG. 7illustrates the resuscitation device 1 in a potential commercialembodiment. The support board 6 is sized to reach approximately from thelower lumbar region to the shoulders of a victim. The compression module26 is separable from the support board 6, and includes the compressionbelt and friction vest stored within the compression module. The spoolassembly and motor are also stored within the compression module,although the motor may also be installed in the support board. In thisfigure, the compression module comprises a small support board 27 whichfits into the larger system support board 28. Taking advantage ofavailable space in the system support board, a compartment 29 forstorage of airway management devices (bag masks, oxygen masks, etc.),and a compartment 30 for storage of defibrillation equipment (electrodesand paddles, etc.) are included with the support board. A control andcommunication module 31 may also be incorporated into the support board.A small oxygen bottle 32 may be included, along with hoses routed to anaccessible point on the board, and any connector desired for connectionbetween the oxygen bottle and devices provided in the airway managementcompartment. Batteries 23 are stored within the support board (thenumber of the batteries chosen according the desired operating time, andthe placement of the batteries dictated by available space). Batteriesare operably connected to the motor in the compression module throughelectrical connectors 33 and appropriate wiring throughout the supportboard. The batteries can also be operably connected to thedefibrillation module and control and communications module. Althoughlong life batteries can be used, rechargeable batteries may bepreferred. Accordingly, charging connection 34 on the support board isprovided for charging the batteries or operating the device throughoutside power supplies.

The device is intended to be stored for long periods of time betweenuses, and storage holder 35 is provided for this purpose. The storageholder can include such necessities as power supply connectors, powerplug, and a charging transformer. A removal sensor 36 is included in thesupport board to sense when the support board is removed from thestorage holder (which, as described below, can be used as a conditionindicating use of the device, and therefore the need to alert emergencymedical personnel). The removal sensor can comprise a simple limitswitch which senses physical removal of the system, and the limit switchcan be used as a power switch or awaken switch which starts initiationof the system. The removal sensor can comprise a current sensor on thecharging lines which treat cessation of charging current, increase incurrent draw through the charging system, or motor current as anindication of use. The choice of sensor may be made with many practicalconsiderations in mind, such as the desire to avoid treating poweroutages as indications of use and other such unintended initiations. Thestate in which the device is deemed to be “in use” can be chosenaccording to the practical considerations, and in most instances it isexpected that mere removal of the resuscitation device from the holderwill constitute a clear signal someone has determined that a victimrequires its use, and that emergency medical personnel should bedispatched to the location of the device. There are some environments inwhich later conditions will be used to indicate that the device is “inuse,” such as when installed in ambulances, airplanes, hospitals orother environments where it might be advisable to remove the device fromits storage holder as a precaution or preparatory measure, and delayinitiation of communications until the device is deployed or installedon the victim. In such cases, the buckle latch shown in FIG. 3 can beused as the sensor that indicates that the resuscitation device is inuse.

FIG. 8 shows the details of the compression module 26. When not in use,the module is covered with a tear sheet 37 that protects the compressionbelt from wear. The buckles are readily visible under the tear sheet.The electrical connectors 38 connect the batteries in the support boardwith the motor inside the compression module. The inside of thecompression belt is fitted with penetrating electrodes 39 in the rightsternum parasaggital location 40 and left rib medial location 41 forestablishing the electrode contact needed for EKG sensing. Theseelectrodes may be dispensed in environments where proper placement ofthe defibrillation electrodes can be assumed due to a high level oftraining amongst likely bystanders and first responders. The frictionvest 5 is secured to the compression module above the spool assemblylocation.

FIG. 9 shows a detail view of the defibrillation module in thecompartment 30. The defibrillation module includes a pair ofdefibrillation electrodes 42 connected to the batteries through thepower connections 43. The defibrillation electrodes will be controlledby circuitry housed within the defibrillation module, and may beconnected to the control module through the data port 44. Thedefibrillation module is releasably attached to the support board 28with quick release latches 51. Tear sheet 46 protects the components ofthe defibrillation module during storage and provides ready access foruse. FIG. 10 shows the detail view of the airway management module inthe compartment 29, which includes an oxygen mask 47, a length of tubing48 and an air fitting 49 connecting the oxygen mask to the oxygen bottlewithin the support board. The oxygen mask serves as a blood gas exchangemeans, supplying oxygen to the lungs for exchange with blood gas such asCO₂. Optional medicine injectors 50 may be operably connected to themasks or hose to provide for automatic injection of ACLS medicationsinto the airway. The defibrillation module is releasably attached to thesupport board 28 with quick release latches 51. Tear sheet 46 protectsthe components of the airway management module during storage andprovides ready access for use. An end-tidal CO₂ monitor 52 can beincluded in the mask to provide for biological feedback and monitoringof the success of the CPR. A skin mounted blood oxygen level monitor 53can also be mounted on the mask for the same purpose (fingertip bloodoxygen sensors may also be used, and supplied in the overall assembly tobe readily available). The biological data obtained by the sensors istransmitted to the control module via appropriate wiring in the mask andsupport board.

FIG. 11 shows a detail view of the control and communications module.The control unit 54 is connected to the compression module,defibrillation module and the airway management module throughappropriate wiring through the support board. The control unit isoptionally connected to the communications unit 55. The communicationsunit includes means for communicating the EKG and other measured medicalparameters sensed on the board to the screen 56 and via telephone toremote medical personnel. The communications unit can include atelephone handset or speakerphone. Because the device is most likely tobe used at a location separate from the storage holder, thecommunications module preferably includes a wireless communicationdevice, such as wireless telephone, radio telephone or cellular, and anynecessary telephone base will be installed in the storage holder.

The communications unit and control unit are set up to operate in thefollowing manner, also illustrated in the block diagram of FIG. 12. Thedevice may remain mounted in a charging unit for months between uses,and will be removed from the charging unit for use. Upon removal of thedevice from its storage location, a sensor in the control unit sensesthe removal (through limit switches, magnetic switches, or motionsensors, current sensors in the charging system, or otherwise) andinitiates the system, checking functions, energizing a display unit andaccomplishing other typical warm-up functions. As a first step, thesystem initiates a telephone communication with a medical facilitythrough the communications unit. The communication may use anycommunication medium, whether it be standard telephone lines, cellulartelephone system, paging system or radio transmitter. The system may beset up to initiate communications with central medical facility, such asa local 911 emergency system, a nearby hospital or ambulance service, ora central facility staffed with medical personnel trained specificallyon the remote use of the device (all generally referred to as medicalpersonnel). Upon establishing communication, the communications unitinforms medical personnel of the location or identification of thedevice (which may be stored in computer memory in the communicationsunit, or determined through GPS or other such system), and thisinformation can be used to dispatch an emergency medical team to thelocation of the device. In a simple embodiment which does not require acomputer to control the actions of the alert feature, the removal sensormay comprise a limit switch, while the communications module maycomprise a simple telephone unit installed in the storage holdertogether with a tape recorded message, where the operation of the relayin response to removal of the resuscitation device includes initiationof the telephone call to 911 and playback of an alert message providingalert information such as the location of the board. The communicationsunit may also be provided with an alert button that may be operated by abystander regardless of the use of the board to summon an emergency teamto the location regardless of the condition of the resuscitation device.

Before the emergency medical team arrives, a bystander will place theboard under the victim, buckle the compression belt around the victimand apply defibrillation and/or sensing electrodes (or viceversa)(alternatively, sensing electrodes can be included on the innersurface of the compression belt). The system monitors the installationof the belt through signals provided through latching sensors in thebuckle. The system monitors biological input, which can comprisemonitoring of EKG signals from the EKG electrode patches of thedefibrillation module, monitoring EKG signals belt mounted electrodes,monitoring signals from an end-tidal CO₂ monitor from the airwaymanagement module, and any other biological signal sensor incorporatedinto the device. The system can also monitor or respond to manuallyinputted instruction from the control unit, in order to provide on-siteemergency medical personnel with control of the device when they arriveon scene. During operation, the system transmits all availablebiological information, including EKG signals, blood pressure, end-tidalCO₂ and any other monitored biological parameter to the remote medicalfacility, and it can also transmit information regarding theconfiguration of the device, including battery life, system operatinglimit settings (i.e., whether the system is set for automatic operation,permissive operation, or disabled in any function) so that medicalpersonnel can ensure that the appropriate configuration is in effect.

Communication with the medical facility will allow emergency medicalpersonnel to diagnose the condition of the patient and, through signalssent from the medical personnel to the communications unit, permit,initiate or prohibit certain additional therapeutic ACLS actions. Forexample, upon diagnosing the EKG conditions that indicate the need fordefibrillation, the medical personnel can send a signal to thecommunications unit that acts upon the control unit to permit manualoperation of the defibrillation electrodes by the bystander. The systemalso provides for application of a defibrillation shock via remotesignal from the medical personnel. The device can incorporate the expertsystem such as the Automatic External Defibrillator. The medicalpersonnel can also communicate other actions, and ensure that certainacts are undertaken by the bystander through the communication system.For example, the medical personnel may communicate verbally with thebystander to ascertain the cause of the cardiac arrest, the properplacement of the oxygen mask, appropriate clearing of the airway, andother information. Where the airway management module is provided withmedication such as epinephrine, lidocaine, bretylium or other drugscalled for in the ACLS guidelines (or newly proposed drugs such as T3),the medical personnel can instruct by-standers to inject appropriatemedication through the airway. Where automatic injectors such as thosedescribed in Kramer, Interactive External Defibrillation and DrugInjection System, U.S. Pat. No. 5,405,362 (Apr. 11, 1995) are provided,or similar system with non-osseous injectors are provided, the medicalpersonnel can instruct by-standers to inject appropriate medicationthrough these injectors. Where the injectors are provided with means forautomatic operation based on measured EKG signals, blood pressure andend-tidal CO₂, the medical personnel can send signals to the system toinitiate injection by remote control of the medical personnel, permitinjection by local control as determined by the expert system, permitinjection by by-standers, or prohibit injection by the system orbystanders. For example, the system can be initially set up to forbidany injection. Medical personnel, having diagnosed ventricularfibrillation through the information provided by the communicationsunit, can send an appropriate signal to permit or initiate injection ofepinephrine, and also send a signal to prohibit injection of atropineuntil called for under the ACLS guidelines. A newly proposed drug T3 canbe administered through the airway, into the lungs, as a therapy forcardiac arrest. Controlled injection into the airway can be initiated orprohibited in the same manner. Thus, all actions in the ACLS, includingcompression, defibrillation, and drug injection can be accomplishedthrough the system under the guidance of medical personnel from a remotelocation, or they may be accomplished through expert systems installedin the control module. Each of these functions is incorporated in asystem that automatically initiates communication with medical personneland informs medical personnel of the location of the device so thatemergency medical personnel may be dispatched to the location.

The repeated compression will be initiated upon buckling of thecompression belt (automatically) or a switch can be provided for thebystander to initiate compression. The system will continue compressioncycles, until de-activated, according the motor control block diagram ofFIG. 13. Upon initiation of the system, the control unit will monitorinstallation of the belt via appropriate sensors in the buckles orthrough other sensors. When the motor control 57 receives the initiatecompression signal from the control unit, the motor is started. Themotor is preferably run continuously, rather than stopped and started,to avoid repeated application of startup current and thus conservebattery power. When the motor is up to speed, the clutch is engaged. Asa baseline, the clutch is engaged every second for one-half second. Thiscyclic engagement of the clutch continues repeatedly for five cycles, asrecommended by current CPR guidelines, and then is interrupted for arespiration pause, if desired. To avoid excessive drain on thebatteries, the motor controller includes a torque sensor (sensingcurrent supply to the motor, for example), and monitors the torque orload on the motor. A threshold is established above which furthercompression is not desired or useful, and if this occurs during the halfsecond of clutch engagement, then the clutch is disengaged and the cyclecontinues. The system can monitor the effectiveness of the compressionstroke by monitoring the CO₂ content of the victim's exhalant. Where CO₂content is low, indicating inadequate circulation, the control systemincreases the torque limit until the CO₂ levels are acceptable (or untilthe maximum torque of the motor is achieved.) This is another example ofthe device's use of biological signals to control operation of thesystem. The cycle time and period, number of cycles between respirationpauses, and the torque limit, can be set according to currentguidelines, and can also be varied by the remote medical personnel viathe remote control capabilities of the control unit.

Thus, while the preferred embodiments of the devices and methods havebeen described in reference to the environment in which they weredeveloped, they are merely illustrative of the principles of theinventions. Other embodiments and configurations may be devised withoutdeparting from the spirit of the inventions and the scope of theappended claims.

1. A resuscitation and alert system comprising: a resuscitation devicecomprising a defibrillator; sensing means for determining when theresuscitation device is in use and generating and transmitting a signalindicating that the resuscitation device is in use; communicating meansfor enabling oversight and communication with remote emergency medicalpersonnel; and a means for measuring the cardiac electrical activity ofa patient and generating and transmitting an EKG signal corresponding tothe cardiac electrical activity; a processor for receiving input fromthe sensing means, controlling the defibrillator and controlling thecommunicating means to initiate communication with the remote emergencymedical personnel whenever the input from the sensing means indicatesthat the device is in use, and to communicate the EKG signal to theremote emergency medical personnel when the means for measuring measuresthe cardiac electrical activity, the processor further controllingoperation of the defibrillator according to enable signals transmittedby the remote emergency medical personnel.
 2. The resuscitation andalert system of claim 1 wherein: the processor is programmed to causethe defibrillator to deliver a therapeutic shock to the patient when theprocessor receives an initiate signal.
 3. The resuscitation and alertsystem of claim 1 wherein: the processor is programmed to analyze theEKG and determine the need for therapeutic shock, and cause thedefibrillator to deliver a therapeutic shock to the patient when theprocessor determines the need for therapeutic shock and the remoteemergency medical personnel have provided an enable signal.
 4. Theresuscitation and alert system of claim 1 wherein: the communicationmeans is capable of allowing communication between a rescuer and theremote emergency medical personnel, whereby the rescuer operates thedefibrillator to deliver a therapeutic shock to the patient wheninstructed by the remote emergency medical personnel and the remoteemergency medical personnel have provided the enable signal.